Page 27 - Noninvasive Diagnostic Techniques for the Detection of Skin Cancers

thus increasing the number of melanomas that are identified and sent for biopsy, while reducing
the number of unnecessary biopsies. It may even allow melanomas to be identified at earlier
stages which could lead to better outcomes.
Only one RCT examined this posited advantage of increased diagnostic accuracy of
dermoscopy compared with naked eye examination. This RCT compared dermoscopic
evaluation and naked-eye examination in 73 primary care physicians in Italy and Spain and
inferred the effect of the addition of dermoscopy on the likelihood that a primary care physician
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would fail to refer a patient with suspicious skin lesions for a second expert opinion.
One RCT of 913 patients in Italy examined the downstream effect on the number of skin
lesion excised for diagnostic verification with the addition of dermoscopy in a pigmented lesion
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clinic.
The use of dermoscopy may help to allay patient anxiety as one survey reported that more
than half of the dermatologists queried responded that dermoscopy was effective in reducing
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patients’ anxiety.
One author suggested that followup examination using digital dermoscopy would allow for
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the detection of early stage melanoma. We did not identify any controlled studies examining
the use of dermoscopy to increase the detection rate of early stage melanoma. The studies on
early melanoma identified by this brief were largely confined to the use of algorithms or
classifiers of dermoscopic images to differentiate early melanoma from other stages of
melanoma.

Theoretical Disadvantages
The use of dermoscopy requires training and this may be considered a theoretical
disadvantage for those who are not willing to invest in the time and effort to learn and master this
technique. Based on our key informant interviews, we were informed that one of the main
challenges to the use of dermoscopy lies in the training of nonexperts in its technique. The level
of training and experience of the user may well determine the effectiveness of dermoscopy. A
review paper recommended that dermoscopy should be used by experts to increase test
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accuracy.
The time necessary to complete an examination using the technique may be considered a
negative factor in its use. In one study, almost one-third of dermatologists thought that the use of
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dermoscopy was too time consuming. An RCT found that performing a complete skin
examination with dermoscopy took significantly longer compared with a complete skin
examination without dermoscopy (median time was 142 vs. 72 seconds, respectively;
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P<0.001). Although one key informant suggested that since the total time required for a
thorough complete skin examination (with or without dermoscopy) was generally less than 3
minutes, it is not an reasonable amount of time considering that it could potentially prevent the
morbidity and mortality associated with skin cancer. Another comparative study found that the
use of dermoscopy is more time consuming compared with total body photography. The time
spent at initial visit was 30 to 50 minutes for dermoscopic photographs and 20 to 30 minutes for
TBP. Follow-up visit time was also longer with dermoscopic photographs lasting 30 to 50
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minutes compared with 10 to 20 minutes for TBP.
No study systematically assessed harms to either the patients or the operators from the use of
dermoscope. Unintended effects from the use of dermoscope were described in two case reports.
One case report described a patient who developed allergic contact dermatitis after exposure to
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dermoscopy immersion oil contaminated with cedarwood oil. The other described a

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